Perishable items, such as chilled and minimally processed food items, vaccines, pharmaceuticals, blood, film, chemicals, adhesives, paint, munitions, batteries, soft drinks, beer, cosmetics, and many other items, each have a unique shelf life. Item quality is affected by a number of factors that may be physical, chemical or biological in nature, and that act together in often complex and interconnected ways. Temperature is usually a significant factor determining the longevity of quality. Sensors have been proposed to monitor and report the shelf life or integrity of an item (e.g. how well the quality of the item has been maintained over time). U.S. patent application Ser. No. 11/112,718 (the '718 application), which is assigned to the present assignee and which is incorporated herein by reference, describes a class of sensors that utilize RF technology for communicating precise, temperature-dependent, shelf life, and other time-dependent sensor monitoring of perishable items. The sensors may operate in conjunction with RF transponders (also known as RFID or radio frequency identification devices), such as those used for tracking and tracing items. For example, the sensors may be directly or indirectly coupled to and/or integrated with an RF transponder.